Terrestrial Ecosystems

Question 1

what are some direct effects of climate change on ecosystems

Answer 1

• shifts in ecosystem types
• migration of species
• changes in species interactions and food webs
• spread of diseases

Question 2

describe poleward-shifting habitat zones

Answer 2

• as the climate changes, the land zones suitable for a particular species shift geographically
• shift is typically poleward, consistent with warming

Question 3

describe upward-shifting habitat zones

Answer 3

• biomes will shift upwards in elevation
• in mountainous landscapes, temp decreases with increasing altitude, so warming would lead to an upward shift in habitat zones

Question 4

describe the effect of habitat shifting on species

Answer 4

• some species can adapt to moving to a new landscape faster than others
• fastest: self-hoofed mammals, carnivorous mammals, freshwater mollusks, plant-feeding insects
• slowest: trees, primates, rodents

Question 5

describe the effect of climate change on the mountain pine beetle

Answer 5

• species of bark beetle native to the forests of western North America
• decomposer, so it attacks old or weakened trees & speeding development of a younger forest
• population kept under control by cold temps, which kill off the beetles
• since summers & winters have been warmer, there are fewer episodes of extreme cold
• lead to an unprecedented explosion in their population

Question 6

describe the potential impact on terrestrial echtotherms

Answer 6

• ectotherms or cold-blooded animals can’t maintain a constant internal body temperature
• tropical ectotherms have a narrow range of temp tolerance, so they live in environments where body temps are near or above optimal temperatures
• since they have small tolerances, expect that tropical ectotherms will be more vulnerable to rising temps

Question 7

case study: northern leopard frog

Answer 7

• with warming temps, by 2100 the range of the northern leopard frog moving poleward

Question 8

case study: american pika

Answer 8

• small mammal that lives in the mountains of the Western US, including the Sierra Nevada
• very sensitive to heat, can die from prolonged exposure to temps a low as 78F
• five-fold increase in local extinctions from 1998-2008 compared with the 20th century
• low-elevation boundary of the pika habitat range is shifting upward in elevation, about 145m per decade

Question 9

describe an invasive species

Answer 9

• disrupts local ecosystem

- usually they have no natural predator, so their population remains unchecked

Question 10

describe the impact of climate change on flood frequency

Answer 10

• in the tropical & mid-latitude area, increase in extreme precipitation is also projected
• the number of storms doesn’t change significantly, so the amount of rainfall produced in the storms has to increase
• Clausius-Clapeyron: if there is more water vapor in the air in a warmer climate –> rising motion –> more rain
• leads to an increased risk of flooding

Question 11

describe the anticipated rain increase under RCP8.5

Answer 11

• increase in extreme precipitation is about 50% in the most likely case by the end of the century
• on the wettest 5% of days, precipitation will go up by about 50%

Question 12

describe the effect on wildfires

Answer 12

• increased risk of fire in areas where decades of total fire suppression have resulted in buildup of dead fuels
• predicted to increase in frequency, size, season length
• dependent on factors like: longer, more intense summer droughts stressing trees; stressed trees are more susceptible to attacking beetles which leave standing dead fuels in their wake

Question 13

describe land protection

Answer 13

• some of the impacts of climate change can be mitigated by establishing protected areas, where human activities are limited to a certain degree
• purpose is to protect biodiversity to promote human well-being